scholarly journals Boosting Performance of Self-Polarized Fully Printed Piezoelectric Nanogenerators via Modulated Strength of Hydrogen Bonding Interactions

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1908
Author(s):  
Hai Li ◽  
Sooman Lim
Keyword(s):  
Hydrogen Bonding ◽  
Composite Film ◽  
High Performance ◽  
Composite Films ◽  
Β Phase ◽  
Hydrogen Bonding Interactions ◽  
Barium Titanate Nanoparticles ◽  
Surface Modified ◽  
Piezoelectric Devices ◽  
Piezoelectric Nanogenerators

Self-polarized piezoelectric devices have attracted significant interest owing to their fabrication processes with low energy consumption. Herein, novel poling-free piezoelectric nanogenerators (PENGs) based on self-polarized polyvinylidene difluoride (PVDF) induced by the incorporation of different surface-modified barium titanate nanoparticles (BTO NPs) were prepared via a fully printing process. To reveal the effect of intermolecular interactions between PVDF and NP surface groups, BTO NPs were modified with hydrophilic polydopamine (PDA) and hydrophobic 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES) to yield PDA-BTO and PFD-BTO, respectively. This study demonstrates that the stronger hydrogen bonding interactions existed in PFD-BTO/PVDF composite film comparative to the PDA-BTO/PVDF composite film induced the higher β-phase formation (90%), which was evidenced by the XRD, FTIR and DSC results, as well as led to a better dispersion of NPs and improved mechanical properties of composite films. Consequently, PFD-BTO/PVDF-based PENGs without electric poling exhibited a significantly improved output voltage of 5.9 V and power density of 102 μW cm−3, which was 1.8 and 2.9 times higher than that of PDA-BTO/PVDF-based PENGs, respectively. This study provides a promising approach for advancing the search for high-performance, self-polarized PENGs in next-generation electric and electronic industries.

scholarly journals Actuation Behavior of Multilayer Graphene Nanosheets/Polydimethylsiloxane Composite Films

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1243 ◽  
Author(s):  
Chunmei Zhang ◽  
Tianliang Zhai ◽  
Chao Zhan ◽  
Qiuping Fu ◽  
Chao Ma
Keyword(s):  
Composite Film ◽  
High Performance ◽  
Graphene Nanosheets ◽  
Composite Films ◽  
Multilayer Graphene ◽  
Layer By Layer ◽  
Pdms Film ◽  
Out Of Plane ◽  
Dielectric Actuation ◽  
Electromechanical Actuation

The graphene nanosheets (GNS)/polydimethylsiloxane (PDMS) composite films with out-of-plane dielectric actuation behavior were prepared through a layer-by-layer spin coating process. The GNS-PDMS/PDMS composite films with 1~3 layers of GNS-PDMS films were spin coated on top of the PDMS film. The dielectric, mechanical, and electromechanical actuation properties of the composite films were investigated. The dielectric constant of the GNS-PDMS3/PDMS composite film at 1 kHz is 5.52, which is 1.7 times that of the GNS-PDMS1/PDMS composite film. The actuated displacement of the GNS-PDMS/PDMS composite films is greatly enhanced by increasing the number of GNS-PDMS layers. This study provides a novel alternative approach for fabricating high-performance actuators with out-of-plane actuation behavior.

scholarly journals Mechanically Robust Flexible Multilayer Aramid Nanofibers and MXene Film for High-Performance Electromagnetic Interference Shielding and Thermal Insulation

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3041
Author(s):  
Jun Zhou ◽  
Junsheng Yu ◽  
Dongyu Bai ◽  
Huili Liu ◽  
Lu Li
Keyword(s):  
Mechanical Properties ◽  
Composite Film ◽  
Electromagnetic Interference ◽  
Multilayer Structure ◽  
High Performance ◽  
Composite Films ◽  
Next Generation ◽  
Shielding Effectiveness ◽  
Breaking Strain ◽  
Practical Applications

In order to overcome the various defects caused by the limitations of solid metal as a shielding material, the development of electromagnetic shielding materials with flexibility and excellent mechanical properties is of great significance for the next generation of intelligent electronic devices. Here, the aramid nanofiber/Ti3C2Tx MXene (ANF/MXene) composite films with multilayer structure were successfully prepared through a simple alternate vacuum-assisted filtration (AVAF) process. With the intervention of the ANF layer, the multilayer-structure film exhibits excellent mechanical properties. The ANF2/MXene1 composite film exhibits a tensile strength of 177.7 MPa and a breaking strain of 12.6%. In addition, the ANF5/MXene4 composite film with a thickness of only 30 μm exhibits an electromagnetic interference (EMI) shielding efficiency of 37.5 dB and a high EMI-specific shielding effectiveness value accounting for thickness (SSE/t) of 4718 dB·cm2 g−1. Moreover, the composite film was excellent in heat-insulation performance and in avoiding light-to-heat conversion. No burning sensation was produced on the surface of the film with a thickness of only 100 μm at a high temperature of 130 °C. Furthermore, the surface of the film was only mild when touched under simulated sunlight. Therefore, our multilayer-structure film has potential significance in practical applications such as next-generation smart electronic equipment, communications, and military applications.

Porous, Multi-layered Piezoelectric Composites Based on Highly Oriented Pzt/pvdf Electrospinning Fibers for High-performance Piezoelectric Nanogenerators

2021 ◽  
Author(s):  
Xiangxin Du ◽  
Zheng Zhou ◽  
Zhao Zhang ◽  
Liqin Yao ◽  
Qilong Zhang ◽  
...  
Keyword(s):  
Porous Structure ◽  
High Performance ◽  
Mechanical Energy ◽  
High Sensitivity ◽  
Fiber Composites ◽  
Piezoelectric Composites ◽  
Β Phase ◽  
Energy Harvesting Devices ◽  
Piezoelectric Nanogenerators ◽  
Piezoelectric Fiber

Abstract Piezoelectric nanogenerators (PENGs) that can harvest mechanical energy from ambient environment have broad prospects for multi-functional applications. Here, multi-layered piezoelectric composites with a porous structure based on highly oriented PZT/PVDF electrospinning fibers are prepared via a laminating method to construct high-performance PENGs. PZT particles as piezoelectric reinforcing phases are embedded in PVDF fibers and facilitate the formation of polar β phase in PVDF. The multi-layered, porous structure effectively promotes the overall polarization and surface bound charge density, resulting in highly efficient electromechanical conversion. The PENG based on 10 wt.% PZT/PVDF composite fibers with a 220 µm film thickness output an optimal voltage of 62.0 V and a power of 136.9 μW, which is 3.4 and 6.5 times the voltage and power of 10wt.% PZT/PVDF casting film-based PENG, respectively. Importantly, the PENG shows a high sensitivity of 12.4 VN-1, presenting a significant advantage in comparison to PENGs with other porous structures. In addition, the composites show excellent flexibility with a Young’s modulus of 227.2 MPa and an elongation of 262.3%. This work shows great potential application of piezoelectric fiber composites in flexible energy harvesting devices.

scholarly journals Investigation of the solvent-dependent photolysis of a nonnucleoside reverse-transcriptase inhibitor, antiviral agent efavirenz

2017 ◽  
Vol 25 (3) ◽  
pp. 94-104
Author(s):  
Maryam A Jordaan ◽  
Michael Shapi
Keyword(s):  
Hydrogen Bonding ◽  
High Performance ◽  
Antiviral Agent ◽  
Energy Shift ◽  
Transcriptase Inhibitor ◽  
Intramolecular Proton Transfer ◽  
Biologically Active ◽  
Hydrogen Bond Donor ◽  
Flight Mass Spectrometry ◽  
Hydrogen Bonding Interactions

This study sought to investigate the solvent-dependency on the photolysis of efavirenz to gain insight into the photoprocesses involved. The primary mechanisms were firstly the excited-state intramolecular proton transfer (i.e. phototautomerization), which generated the imidic acid phototautomer observed as [M-H]− quasimolecular ion at m/z 314.0070 in the high-performance liquid chromatography–electrospray ionization–time-of-flight mass spectrometry in the negative mode. Secondly, the photoinduced α-cleavage with the loss of a carbonyl group occurred (i.e. photodecarbonylation) to form the photoproduct at m/z 286.0395. The ultraviolet–visible spectra illustrated a large, hyperchromic, and slight bathochromic effect in both the π→π* and n→π* electronic transitions. The largest bathochromic effect was prevalent in the chloroform solvent, i.e. chloroform (π* = 0.58; β = 0.00; α = 0.44) > methanol (π* = 0.60; β = 0.66; α = 0.98) > acetonitrile (π* = 0.75; β = 0.40; α = 0.19). This is due to the significant interaction of the amino group with the excited carbonyl moiety which is attributed to intramolecular phototautomerization resulting in a larger energy shift of the electronic state. A plausible explanation is due to the hydrogen bond donor ability of the polar methanol and nonpolar chloroform solvents, which stabilized the polarized imidic acid phototautomer by means of hydrogen bonding interactions, as opposed to the aprotic acetonitrile which exhibits no hydrogen bonding interactions. The study would form the basis for further photolytic analyses and syntheses to generate a plethora of novel photoproducts with anti-HIV activity based on the biologically active benzoxazinone framework of efavirenz.

scholarly journals High performance polypyrrole/SWCNTs composite film as a promising organic thermoelectric material

RSC Advances ◽  
2021 ◽  
Vol 11 (29) ◽  
pp. 17704-17709
Author(s):  
Zhaohua Liu ◽  
Jiye Sun ◽  
Haijun Song ◽  
Yicheng Pan ◽  
Yufei Song ◽  
...  
Keyword(s):  
Low Temperature ◽  
Composite Film ◽  
Thermoelectric Material ◽  
High Performance ◽  
Interfacial Polymerization ◽  
Composite Films ◽  
Thermoelectric Performance

PPy/SWCNTs composite films with high thermoelectric performance were prepared by chemical interfacial polymerization under a controlled low temperature.

scholarly journals Porous, multi-layered piezoelectric composites based on highly oriented PZT/PVDF electrospinning fibers for high-performance piezoelectric nanogenerators

2022 ◽  
Vol 11 (2) ◽  
pp. 331-344
Author(s):  
Xiangxin Du ◽  
Zheng Zhou ◽  
Zhao Zhang ◽  
Liqin Yao ◽  
Qilong Zhang ◽  
...  
Keyword(s):  
Porous Structure ◽  
High Performance ◽  
Mechanical Energy ◽  
High Sensitivity ◽  
Fiber Composites ◽  
Piezoelectric Composites ◽  
Β Phase ◽  
Energy Harvesting Devices ◽  
Piezoelectric Nanogenerators ◽  
Piezoelectric Fiber

AbstractPiezoelectric nanogenerators (PENGs) that can harvest mechanical energy from ambient environment have broad prospects for multi-functional applications. Here, multi-layered piezoelectric composites with a porous structure based on highly oriented Pb(Zr0.52Ti0.48)O3/PVDF (PZT/PVDF) electrospinning fibers are prepared via a laminating method to construct high-performance PENGs. PZT particles as piezoelectric reinforcing phases are embedded in PVDF fibers and facilitate the formation of polar β phase in PVDF. The multi-layered, porous structure effectively promotes the overall polarization and surface bound charge density, resulting in a highly efficient electromechanical conversion. The PENG based on 10 wt% PZT/PVDF composite fibers with a 220 µm film thickness outputs an optimal voltage of 62.0 V and a power of 136.9 µW, which are 3.4 and 6.5 times those of 10 wt% PZT/PVDF casting film-based PENG, respectively. Importantly, the PENG shows a high sensitivity of 12.4 V·N−1, presenting a significant advantage in comparison to PENGs with other porous structures. In addition, the composites show excellent flexibility with a Young’s modulus of 227.2 MPa and an elongation of 262.3%. This study shows a great potential application of piezoelectric fiber composites in flexible energy harvesting devices.

scholarly journals Preparation and Characterization of Thermoelectric PEDOT/Te Nanorod Array Composite Films

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 148
Author(s):  
Hong-Ju Ahn ◽  
Seil Kim ◽  
Kwang Ho Kim ◽  
Joo-Yul Lee
Keyword(s):  
Composite Film ◽  
High Performance ◽  
Electrochemical Polymerization ◽  
Composite Films ◽  
Lithium Perchlorate ◽  
Nanorod Array ◽  
Energy Filtering ◽  
Carrier Energy ◽  
Galvanic Displacement Reaction ◽  
Filtering Effect

In this study, we prepared Te nanorod arrays via a galvanic displacement reaction (GDR) on a Si wafer, and their composite with poly(3,4-ethylenedioxythiophene) (PEDOT) were successfully synthesized by electrochemical polymerization with lithium perchlorate (LiClO4) as a counter ion. The thermoelectric performance of the composite film was optimized by adjusting the polymerization time. As a result, a maximum power factor (PF) of 235 µW/mK2 was obtained from a PEDOT/Te composite film electrochemically polymerized for 15 s at room temperature, which was 11.7 times higher than that of the PEDOT film, corresponding to a Seebeck coefficient (S) of 290 µV/K and electrical conductivity (σ) of 28 S/cm. This outstanding PF was due to the enhanced interface interaction and carrier energy filtering effect at the interfacial potential barrier between the PEDOT and Te nanorods. This study demonstrates that the combination of an inorganic Te nanorod array with electrodeposited PEDOT is a promising strategy for developing high-performance thermoelectric materials.

Electrically excited oscillation and crystalline structure of a nanoclay/poly(vinylidene fluoride) composite film

2011 ◽  
Vol 22 (18) ◽  
pp. 2103-2112 ◽  
Author(s):  
Go Murasawa ◽  
Akihiro Nishioka ◽  
Ken Miyata ◽  
Tomonori Koda ◽  
Hideo Cho
Keyword(s):  
Composite Film ◽  
Crystalline Structure ◽  
Vinylidene Fluoride ◽  
Composite Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Impedance Characteristics ◽  
Poly Vinylidene Fluoride ◽  
Excited Oscillation

This study was conducted to investigate electrically excited oscillation and crystalline structure of nanoclay/poly(vinylidene fluoride) (PVDF) composite films. First, nanoclay/PVDF composite films are fabricated by solvent casting. Second, their PVDF crystalline structure and nanoclay orientation are analyzed using x-ray diffraction. The impedance characteristics of films are then measured. Third, the oscillation excited from films as a result of applied voltage is measured. Thereby, we confirmed the presence of unoriented β-phase PVDF crystals and exfoliated-type nanoclay structure in a composite film. The output oscillation showed monotonic component corresponding to the input sinusoidal voltage at a high frequency range, although its amplitude is low.

scholarly journals Bioinspired Dielectric Film with Superior Mechanical Properties and Ultrahigh Electric Breakdown Strength Made from Aramid Nanofibers and Alumina Nanoplates

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3093
Author(s):  
Qiu-Wanyu Qing ◽  
Cheng-Mei Wei ◽  
Qi-Han Li ◽  
Rui Liu ◽  
Zong-Xi Zhang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Hydrogen Bonding ◽  
Composite Film ◽  
Breakdown Strength ◽  
Composite Films ◽  
Electrical Equipment ◽  
Electric Breakdown ◽  
Excellent Thermal Stability ◽  
Practical Applications ◽  
Al2o3 Composite

Materials with excellent thermal stability, mechanical, and insulating properties are highly desirable for electrical equipment with high voltage and high power. However, simultaneously integrating these performance portfolios into a single material remains a great challenge. Here, we describe a new strategy to prepare composite film by combining one-dimensional (1D) rigid aramid nanofiber (ANF) with 2D alumina (Al2O3) nanoplates using the carboxylated chitosan acting as hydrogen bonding donors as well as soft interlocking agent. A biomimetic nacreous ‘brick-and-mortar’ structure with a 3D hydrogen bonding network is constructed in the obtained ANF/chitosan/Al2O3 composite films, which provides the composite films with exceptional mechanical and dielectric properties. The ANF/chitosan/Al2O3 composite film exhibits an ultrahigh electric breakdown strength of 320.1 kV/mm at 15 wt % Al2O3 loading, which is 50.6% higher than that of the neat ANF film. Meanwhile, a large elongation at break of 17.22% is achieved for the composite film, integrated with high tensile strength (~233 MPa), low dielectric loss (<0.02), and remarkable thermal stability. These findings shed new light on the fabrication of multifunctional insulating materials and broaden their practical applications in the field of advanced electrics and electrical devices.

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